Who maintains rotor rpm during power changes and why?

• A. The crew chief or pilot must monitor but the governor maintains the target rotor speed to prevent fluctuations by adjusting collective as needed.
• B. The pilot manually adjusts rotor rpm through throttle control to maintain speed.
• C. The autopilot maintains rotor rpm automatically during power changes.
• D. Rotor rpm is not controlled and varies with power changes.

Answer: (A)

Rotor rpm is kept constant by a governor. In the UH-60, the rotor speed governor continuously monitors the rotor speed (Nr) and automatically adjusts engine input to hold Nr at the preselected target as loads and power demands change. When power increases or a heavier collective input would tend to slow Nr, the governor increases the engine’s torque (and may command small collective or pitch adjustments through the control system) to keep the rotor speed from dropping. Conversely, if Nr tends to rise, the governor trims back engine power to prevent overspeed. The crew chief or pilot watches the Nr indication and can intervene with collective adjustments if needed, but the automatic action that prevents fluctuations during power changes is the governor’s job. This keeps rotor speed stable for consistent lift and rotor authority, so manual, constant throttle control isn’t required. Autopilot systems don’t typically manageNr in normal UH-60 operation, and leaving rotor rpm uncontrolled would lead to instability, which the governor is specifically designed to prevent.